U.S. Pat. No. 4,341,096, assigned to the same assignee, discloses a sock with triple-layer fabric in a substantial portion of the foot for providing cushioning and moisture-absorbing characteristics thereto. The inner and intermediate layers of the foot of the sock of this patent are knit with a lesser number of wales than the number of wales in the outer layer and the remaining portion of the sock. The formation of triple-layer fabric in the foot of the sock may, in some instances, provide more cushioning and a thicker fabric in the foot portion than is desirable. The knitting of the inner and intermediate layers of the sock of said patent with a lesser number of wales than the outer layer and the remaining portions of the sock is accomplished by holding spaced-apart stitch loops on the needles while maintaining these needles in an inactive or nonknitting position during the knitting of the inner and intermediate layers of the foot of the sock.
It is known to knit socks with double-layer fabric in the sole or lower half of the foot, of the type disclosed in U.S. Pat. Nos. 2,714,813 and 3,107,510. U.S. Pat. No. 3,307,379 discloses a sock with double-layer fabric extending throughout the foot and a major portion of the leg, with the double-layer fabric being integrally knit in spaced-apart wales. The knitting of the socks of these three patents requires the use of a knitting machine having two sets of needles with one fabric layer being formed on one set of needles and the other fabric layer being formed on the other set of needles.